auth: adds token-auth to public api

adds auth service
adds auth module
adds token-auth strategy
adds token-auth to all public api calls

Signed-off-by: Philip Molares <philip.molares@udo.edu>

src/auth/token-auth.guard.ts

@@ -0,0 +1,11 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { Injectable } from '@nestjs/common';
+import { AuthGuard } from '@nestjs/passport';
+
+@Injectable()
+export class TokenAuthGuard extends AuthGuard('token') {}